Pump container using laminated bottle with peelable inner layer

ABSTRACT

A pumping container including a laminated bottle having a delaminatable layer with an inner layer portion serving as a valve for closing ventilation holes. The laminated bottle has the inner layer delaminated from an outer layer and formed on its inner surface. A ventilation hole formed in the outer layer allows ambient air to flow in between the outer and inner layers. The ventilation hole in the outer layer is temporarily closed with a closing portion of the inner layer from inside such that this closing portion will be deformed inwards due to atmospheric pressure so as to open the ventilation hole in response to a negative pressure appearing between the layers.

FIELD OF THE INVENTION

The present invention relates to a laminated bottle that has adelaminatable inner layer and an outer layer, wherein the outer layerhas an inner surface on which the inner layer is laminated and has aventilation hole to take ambient air in itself. The invention alsorelates to a pumping container that comprises the laminated bottle andmay be a comb-product or the like, the laminated bottle serving as anreservoir charged with a content such as a hair-dyeing agent.

BACKGROUND OF THE INVENTION

Japanese Patent Laying-Open Gazette No. Hei. 4-267727 discloses amulti-layered container, which is designed such that ambient air isinhibited from entering the container through a mouth and its content isdischarged by the pumping action of an inner layer and an outer layer.This container consists of a bottle and a cap. The bottle is composed ofan impermeable inner layer and a squeezable outer layer. The cap isattached to the mouth of the bottle. The inner layer can be readilydelaminated from the outer layer in which ventilation holes are formedsuch that the ambient air can communicate with the space between thelayers. The cap has a check valve incorporated therein. Therefore, theinner layer of this bottle will naturally shrivel with a decrease in itscontent, with the ambient air flowing into the space through said holesso that only the outer layer can restore and maintain its normalconfiguration. Owing to this feature, its content remains satisfactoryin quality, from the beginning to end of use, without being adverselyaffected by ambient air or external light beams.

The multi-layered container in the prior art has a film tag adhered inpart to the rim of the ventilation hole, and the tag larger than thehole is disposed inside the outer layer. Such a kind of ventilationvalve will allow air to flow inwards penetrating only the outer layerfrom outside. With the container being gripped by a user, theventilation hole will be closed with the valve due to an increasinginner pressure so as not to allow any amount of air to leak out from theinterlayer space. Such a depressed outer layer will raise the interlayerair pressure to thereby depress in a centripetal direction the innerlayer so as to exude the content out of the container.

The prior art method comprising the steps of preliminarily blow moldingor thermally forming the outer layer and subsequently integrating itwith the inner layer does however require so many steps as increasingmanufacture cost of the multi-layered pumping containers and loweringyield thereof. In an alternative method, the laminated bottle with theventilation hole formed solely in the outer layer may be molded, and theventilation valve is then attached to the hole. However, this methodwill also increase the number of steps and necessary parts, inevitablyresulting in a higher manufacture cost.

DISCLOSURE OF THE INVENTION

The present invention provides a laminated bottle having a delaminatinginner layer, and also provides a pumping container comprising thelaminated bottle such that at least one ventilation hole is opened orclosed by and/or with the inner layer itself to take ambient air in aspace between the inner and outer layers, without needing any discreteor additional suction valve. This feature of the invention will beeffective not only to decrease the number of necessary parts but also tosimplify the structure, thus abridging manufacture process and reducingmanufacture cost. Further, the inner layer may have a closing portioncapable of elastic recovery to temporarily close the at least oneventilation hole formed in the outer layer, hereby the air between theselayers is more reliably prevented from leaking out.

In accordance with the present invention, the laminated bottle may havethe delaminating inner layer laminated on the inner surface of the outerlayer and capable of exfoliation therefrom, wherein the at least oneventilation hole is formed in the outer layer to allow ambient air toflow into the space between the outer and inner layers. The ventilationhole in the outer layer may be normally closed with a closing portion ofthe inner layer from inside. The closing portion may function as a valvethat is capable of inward deforming due to atmospheric pressure inresponse to a negative pressure appearing in the space between the innerand outer layers. Because the closing portion provided as an integralpart of the inner layer functions as a valve in the laminated bottle ofthe invention, any discrete or extra valve body need not be mounted,therein. Despite lacking in any discrete valve body, a user does nothave to shut the ventilation hole with his or her fingers when he or shewill squeezes the bottle. As content in the bottle gradually flows orexudes out, the closing portion will be pressed outwards by the content,hereby it will be spontaneously close the ventilation hole.

Preferably, the closing portion of the inner layer may have elasticityfor shape recovering so as to close the ventilation hole. Such a closingportion will restore its natural configuration to close again the outerlayer ventilation hole, upon disappearance of negative pressure withinthe interlayer space due to inflow of a sufficient amount of ambient airinto said space. Thus, the bottle's outer layer may be squeezedsubsequently or later, surely inhibiting the air from flowing out of theinterlayer space.

The laminated bottle of the invention may comprise of a body and amouth, by forming the outer and inner layers to comprise respective bodyparts and respective mouth parts. Preferably, the at least oneventilation hole is formed in the outer layer's mouth part, and theinner layer is made thicker at its mouth part than its body part so asto act as the portion for closing said hole. This structure will enablea cap fitted on the bottle to hide the ventilation hole, affording apleasant appearance to the product, viz., container. In contrast withsuch the mouth part of inner layer made thicker to be capable ofrestoring its normal shape to close said hole, the thinner andfilm-shaped body part of inner layer will readily deflate in the courseof discharging the content. A parison to be blow molded for forming thebottle may be of a uniform thickness from its mouth part to body part,and by stretching only the body part of the parison in the blow moldingstep, it is possible to provide the bottle that the body part of theinner layer is of a film-like shape and the mouth part of the innerlayer is of a layer thickness such as the same has elasticity for shaperecovery. This means that any extra step or additional process is notneeded herein to give the inner layer portion a shape capable ofperforming itself as a kind of valve body.

The mouths of outer and inner layers may be of a cylindrical shape(whether round or elliptic), the ventilation hole may be formed in themouth part of the outer layer, and the mouth part of the inner layer mayact as the closing portion as described above. If the inner layer'smouth part as closing portion is cylindrical, its elastic recovery willbe enhanced to surely seal the ventilation hole.

In the described bottle of this invention, a bottom of the inner layermay comprise a flange fixed on and/or engaging with a bottom of theouter layer, securing these bottoms to each other to prevent the innerlayer's lower end portion from curling up. Preferably, the flange may beformed when molding a inner preform for forming the inner layer byinjecting a molten resin to an interior of an outer preform for formingthe outer layer through a through-hole that is previously formed in abottom of the outer preform.

The laminated bottle having the mouth in the invention may be utilizedto construct any pumping containers for varied uses, if a cap comprisinga check valve is attached to the mouth. Such the pumping containerprovided herein may substantially comprise of the laminated bottle andthe cap fixed on the mouth, wherein the body part of the bottle's outerlayer is capable of being deformed so as to deflate. Also, the cap mayhave an outlet orifice for discharging the content stored within theinner layer out of the inner layer, and a check valve may be attached tothe outlet orifice. The outer layer may be shaped in any proper fashionsuch as a cylinder squeezable in radial direction or as a tubbystructure to be compressible in axial direction.

The laminated bottle may be formed by an appropriate method such asinjection molding and/or blow molding. Examples of the blow molding arethe direct blow molding method and the injection-stretching-blow moldingmethod. Preferably, the latter method may be employed to produce precisemolded products.

Also, the present laminated bottle may be manufactured by a method thatcomprises of the step of injection molding an outer layer preform, thestep of injention molding an inner layer preform inside the outer layerpreform, and the step of blow molding a parison composed of thesepreforms. Further, the ventilation hole may be formed at the step ofinjection molding the outer layer preform, and at least one pin will beinserted into the hole when molding the inner preform.

In this method of making the laminated bottles, the ventilation hole isformed at the step of injection molding the outer layer preform, lestthe inner layer should not be injured. Also, it is no longer necessaryto manually punch the holes in the outer layers one by one afterinjection molding same, thus improving manufacture efficiency.

Those outer and inner layers may have respective molded configurationseach composed of a body portion and a mouth portion to constitute abottle. To protect the mouth portions of the outer and inner layers fromseparation from each other, a relatively large thickness of the innerlayer may for instance be effective. The outer layer will be rendered soeasy to squeeze as enabling it to readily deform itself elastically ifdepressed with a user's hand, or alternatively may be rigid in the eventthat a pump for sucking the content of bottle would be attached to themouth portion.

In the method of making the bottles, the parison may preferably be blowmolded in such a way that the stretching of the parison is effectedbelow its region where the ventilation holes are located. Theventilation holes in this case are protected well from deformation whichthe step of stretching would cause, thereby preventing the resinfractions around the holes from flowing therein to clog same. Stretchingdoes not take place around the ventilation holes, so that a portion ofthe inner layer surrounding the hole will have its wall thickness asthick as the same of the inner preform. Thus, the body part of the innerlayer for containing the liquid content (i.e., the charged content) canbe thinner than the mouth part of the inner layer to be of a film-likeshape and/or structure. At the same time, a portion of the inner layer,which is located adjacent to the ventilation hole, may be thicker thanthe body part of the inner layer so as to be capable of elasticrecovery. The inner layer constructed to naturally close the ventilationholes will however be depressed readily apart from them by external airpressure. It will deform itself inwardly so as to open those holes whenambient air is allowed to enter the interlayer space through them. Theventilation holes behave as if they were valves, so that it is no longernecessary to incorporate any extra or additional valve that wouldincrease the number of constituent parts and raise manufacture cost.

In this method of making the laminated bottles described above, variousappropriate manners may be employed to make the ventilation holes solelyin the outer layer. For example, the outer layer preform may beinjection molded using a cavity segment and a core segment, and then beleft to remain in the cavity segment. The inner layer preform willsubsequently be injection molded using the cavity segment in combinationwith another core segment substituting for the first-mentioned coresegment. In this mode of the method, the ventilation holes may be formedby causing pins to contact the first core segment before the resinbecomes hard at the step of injection molding the outer layer preform.The ventilation holes are allowed to remain closed with the pins whilethe inner layer preform is being injection molded.

Such a method described above may be conducted using the followingapparatus. Namely, this apparatus will be used to produce a parison tobe blow molded into a laminated bottle. The parison is composed of anouter and inner layer preforms and has ventilation holes only in theouter layer at desired portions thereof. A mold constituting thisapparatus may comprise a cavity segment and two discrete core segments,wherein one of the core segments is selected and fastened to the cavitysegment so as to mold the outer layer preform at first, and subsequentlythe other core segment will be used to mold the inner layer preform.Further, this apparatus may comprise pins in connection with the cavitysegment in order to form the ventilation holes. Those pins can shiftthemselves between their projected position contacting thefirst-mentioned core segment and their retracted position embedded inthe cavity segment.

Although the pins in the described example to form ventilation holes arelocated in connection with the cavity segment, they may alternatively bedisposed in a lip segment if the apparatus has same. In this case, thepins at their retracted position will be enclosed with said lip segment.

Further in an alternative method of forming ventilation holes only inthe outer layer preform, this preform will be molded in an injectionmold and then removed therefrom. This outer layer preform is theninserted in a further and separate injection mold for forming the innerlayer preform so that pins equipped in connection with the further moldare inserted from outside into rough ventilation holes that have beenformed. Inner ends of those pins will be brought into flush with theinner surface of the outer layer preform, before the inner layer preformis injection molded.

Such an alternative method described above may be conducted using thefollowing apparatus to produce a parison to be blow molded into alaminated bottle. This parison will also be composed of an outer andinner layer preforms and have ventilation holes only in the outer layerat desired portions thereof. This apparatus may comprise an injectionmold for forming the outer layer preform and a further injection moldfor forming the inner layer preform. Pins for forming the ventilationholes are provided in the first-mentioned mold so as to shift themselvesbetween their projected and retracted positions. The secondly-mentionedmold comprises pin-shaped stoppers that are to be inserted from outsideinto the ventilation holes previously formed in the outer layer preform.

The method described above addresses parisons that are to be blow moldedto give the delaminating types of laminated containers. However thepresent invention is not restricted thereto but is applicable to avariety of injection molded laminated articles (such as laminatedparisons) each composed of two or more resin layers. In other words, thepresent invention proposes a method of making ventilation holes solelyin an outer layer of an injection molded laminated product having aninner layer inside the outer layer. The method may comprise the steps ofinjection molding the outer layer and then molding the inner layer sothat the ventilation holes are formed during the step of injectionmolding the outer layer, wherein the inner layer is injected while pinsremain inserted in the ventilation holes.

The parison-forming mold employed in the apparatus and method of thepresent invention may comprise at least one cavity segment and at leasttwo core segments, larger and smaller. This mold may further comprise aprojectable member that is mounted in the cavity segment so as tocontact the side surface of the larger core segment. An appropriatemeans may also be incorporated to drives pins preferably serving as theprojectable members.

When molding the outer layer preform in the described mold, thispreform's portions where the projectable members are temporarily locatedcan not be filled with a resin for forming this preform. As a result,those portions will define the ventilation holes penetrating thatpreform from an outer surface to inner surface thereof This means thatthe ventilation holes as air passages can be formed already at the sametime as the outer layer preform is molded.

The projectable member incorporated in the mold described above may beheld in and by the lip segment so as to be capable of contacting thecore segment's side face. Alternatively, that member may be held in andby the core segment so as to contact the inner surface of the cavitysegment or the lip segment. In any case, the projectable member maypreferably be located below a threaded portion surrounding a mouth ofthe container that will be produced from the preform.

Also, this method of making the laminated bottles comprises the step offorming one or more ventilation holes that penetrate the outer layerpreform from an outer surface to inner surface thereof, at the same timeas this preform is molded. The ventilation holes are thus formed alreadyat the step of forming the outer layer preform. The present method noweliminates the problem inherent in the prior art that has been injuringthe inner layer when forming the ventilation holes in the outer layerduring the blow molding step. Further, works for manually piercing suchholes one by one in the injection molded outer layer are no longernecessary, thus enhancing manufacture efficiency.

The delaminating inner layer preform is formed herein onto the innersurface of the outer layer preform in such an advantageous manner thattheir portions located below the ventilation holes are subsequentlystretched for orientation.

According to this method, inner layer portions corresponding to theventilation holes maintain an original wall thickness, so that each ofsuch relatively thickened portions may function as a kind of valve bodycooperating with the ventilation hole. Thus, manufacture process becomessimpler and less expensive, as compared with the case of employing extraand discrete valves.

Also in the present method, an inner end of the projectable member maybe located substantially in flush with the inner surface of the outerlayer preform when the inner layer preform is molded using the molddescribed above.

Due to this feature, a resin forming the inner layer preform can beprevented from flowing into portions that have to form the ventilationholes in the outer layer preform.

In the manufacturing methods described above, the ventilation holes maypreferably be formed below a threaded portion of the outer layerpreform.

The laminated bottle with the flange disposed in the inner layer'sbottom may be produced by the following manufacturing method. In themethod providing laminated bottles whose peripheral walls are composedeach of an outer layer and an inner layer disposed therein, a resin ofthe inner layer has a lower melting point than that of the outer layer.In detail, the outer layer preform will preliminarily be injectionmolded, and subsequently the inner layer preform is injection molded onthe inner surface of the outer layer preform by using another resinwhose melting point is lower than that of the outer layer resin. Theparison composed of the outer and inner layer preforms will finally beblow molded. The through-hole mentioned above may be formed in the outerlayer preform when this preform is injection molded, by such anarrangement that a gate penetrating the cavity segment for injection ofthe second resin does face the through-hole. In this case, a moltenresin will be guided through this gate and the through-hole into theinterior of the outer layer that has been placed in the mold forinjection molding the inner layer. In this invention, the inner layerpreform is, molded after the outer layer preform has been molded, asrepeatedly discussed above. Therefore, even if the inner layer preformis made of a polyolefin or the like material and the outer layer preformis made of a ‘PET’, an ‘EVOH’ or the like resin, these two kinds ofresins will not intermix with each other but be demarcated from eachother. Consequently, the laminated bottle made by this method has theinner layer ready to exfoliation from the outer layer during use, thusprotecting a liquid content in this bottle from change in its chemicalproperties. Further, the through-hole in the outer layer preform may beproduced by putting a pin towards the gate so as to bring a free end ofthe pin into contact with the gate, after injection of the resin thoughthe gate. The gate in this case will be sealed up with the pin lest anygate flashes should be produced, thus making it unnecessary to severthem from container bodies.

The flange mentioned hereinbefore is produced of the same resin as theinner layer preform so as to be disposed outside the through-hole duringthe injection molding of the inner layer preform. The flange is integralwith a resin mass disposed in the through-hole and is therefore integralwith the inner layer preform itself. Such a flange is considerablylarger than the through-hole in diameter so that the inner layer can besecurely fixed in part in the outer layer. Due to this feature, astretching rod used at the step of stretching-blow-molding will beprevented from peeling the inner layer off the outer layer. If such aflange is located at the bottom of the bottle, the inner layer will beallowed to delaminate from the outer layer during use, without givingrise to the problem of curling up of the inner layer's lower endportion. Tie ‘flange’ may either be formed in flush with the outersurface of the outer layer, or alternatively, jutting outwards from thethrough-hole.

In case of using the method to manufacture laminated bottles each havinga delaminating inner layer, a resin of the inner layer preform maypreferably be projected out of the through-hole of the outer layerpreform so as to form a stud-shape protrusion, before injection moldingthe inner layer preform. A stretching rod used to carry out the step oflongitudinally stretching the parison will collapse the protrusionstud-shaped and made of the resin forming the inner layer. Thelongitudinal stretching conducted at the step of blow molding will pressthe bottom of the parison to collapse the protrusion to reform it as aflange disposed outside the bottom of outer layer. The inner and outerlayers are thus fixedly secured to each other at their bottoms. In thisway, any additional step is not needed to integrate these layers witheach other at their bottoms.

In addition, the injection molding of the inner layer preform may beconducted such that a plurality of thickened portions are formedintegral with the preform in such a fashion that each portion extendslongitudinally and at angular intervals. Thus, the blow molded laminatedbottles will have each the inner layer that is formed integral withpillaror rib-shaped thickened portions. Those thickened portions willprovide a moderate resistance to deformation such that the inner layeris inhibited from any abrupt and irregular delamination from the outerlayer. Flat regions each interposed between the linear thickenedportions of the inner layer will be caused to make a gradual and inwarddisplacement, to thereby ensure uniform shrivelage and deformation ofthe inner layer over full height thereof in each bottle. Neither amiddle portion of the inner layer nor an upper end portion thereof(located close to the bottle mouth) will shrivel sooner than the lowerportion of the layer. Thus, the latter portion is protected from beingsealed not to exhaust a liquid content. Since the inner layer preform isinjection molded herein, the forming of such thickened portions caneasily be done during the injection molding step in a reliable manner togive products each having a uniform internal texture.

Alternatively, it is possible to provide the inner layer preform with abarrel-shaped part that has a thickened region extending in a helicaldirection. This region may be a helical protrusion formed integral withthe inner surface of the barrel-shaped part. Alternatively, a helicalrecess may be formed in and along the inner surface of the outer layerpreform, and then the inner layer is injection molded inside the outerlayer preform to produce such a helically thickened region.

Also, the injection mold used herein to produce the outer layer preformwith a closed bottom may comprise the cavity segment in combination witha modified core segment having the pin. This pin is intended to contactan inner surface of the closed bottom of the cavity segment. Such a typeof the mold may also be suited to preparation of the outer layer preformin the present invention. If this mold is employed to form an outerlayer, then a space occupied by the pin can not be filled with anyamount of the resin of this preform. Thus a through-hole will beproduced to extend from an outer surface to inner surface of the outerlayer preform. In short, the hole is formed through the bottom of thispreform while molding same.

Alternatively, the injection mold just described above to produce theouter layer preform having the closed bottom for constituting thelaminated container may comprise the at least one core segment and theat least one cavity segment, with the latter segment having a pin tocontact the closed end of the former segment.

Each of these injection molds may have the pin capable of projectinginto and being retracted from a gate so that this gate facing the pin isclogged therewith.

In summary, the laminated bottle of the invention described above may beproduced utilizing the following manufacturing apparatus. This apparatusis composed of a device for injection molding the outer layer, a furtherdevice for injection molding the inner layer, and a still further devicefor blow molding them. A cylindrical outer layer pre-form having abottom and a through-hole formed through the bottom will be injectionmolded by the first-mentioned device. The further device for injectionmolding the inner layer injects an inner layer preform inside the outerlayer preform. The still further device blow molds a parison that isformed with a bottom and composed of the outer and inner layer preforms,while biaxially stretching the parison longitudinally and transverselyin such a way that the inner layer delaminatable from the outer layer islaminated on the inner surface thereof to provide a laminated container.The device for injection molding the inner layer preform may have a gatefor passing a molten resin through the hole to thereby inject it fromoutside into the outer layer preform. The gate may be spaced outwardsfrom the through-hole. Using these devices, the gate formed in a moldfor injecting the inner layer is spaced a distance from the through-holeof the outer layer preform. A portion of the resin for the inner layerpreform protrudes out of the hole and solidifies to be left there, wheninjection molding the inner layer preform with the further device. Atthe step of longitudinally and circumferentially blow molding theparison using the still further device, a stretching rod will collapsethis protrusion when the parison with bottom is longitudinallystretched. Subsequently, the resin will spread on the outer surface ofthe outer layer bottom to engage the inner layer with the outer one atthe bottom of the container. It is possible to form the inner layerusing such a resin as having a lower melting point than that of theouter layer. In other word, it is now possible to choose the mostpreferable resin because the molten resin of the inner layer preform isintroduced through the hole already formed in the bottom of the outerlayer preform, so as to flow on and along the inner surface thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical cross section of a pumping container provided in anembodiment of the present invention;

FIG. 2 also is a side elevation of a comb-shaped product constructedusing a laminated bottle provided in the embodiment,

FIG. 3 is a side elevation of the laminated bottle included in thecomb-shaped product shown in FIG. 2, from which a cap of the comb-likeshape is removed;

FIG. 4 is an enlarged cross section of a principal portion that isincluded in the pumping container shown in FIG. 1.

FIG. 5 is a further enlarged cross section of the principal portionshown in FIG. 4;

FIG. 6 also is a cross section of the pumping container including thelaminated bottle, wherein the container is shown in its entirety and thebottle has its body being gripped;

FIG. 7 is another cross section of the pumping container including thelaminated bottle, wherein the container is shown in its entirety and thebottle is in its non-gripped state;

FIG. 8 is an overall cross section of the pumping container whosecontent has largely been dispensed;

FIG. 9 is an overall vertical cross section of a preform to be blowmolded to give the laminated bottle;

FIG. 10 is a scheme of the step of fastening mold segments together atan injection station (before molding an outer layer preform) in theembodiment of the present invention;

FIG. 11 is a scheme illustrating the injection step conducted at theinjection station (to mold the outer layer preform),

FIG. 12 also is a scheme illustrating the subsequent injection stepcarried out at the injection station (to mold an inner layer preform);

FIG. 13 is a scheme of the transfer step of transferring an integratedpreform at a blowing station;

FIG. 14 is likewise a scheme of the step of fastening the mold andstretching the parison, done at the blowing station;

FIG. 15 is a similar scheme of the step of blowing air into and coolingthe stretched parison, conducted at the blowing station; and

FIG. 16 is a scheme of the step of ejecting a finished molded product atan ejection station so as to take it out.

THE BEST MODE OF CARRYING OUT THE INVENTION

Now some preferred embodiments of the present invention will bedescribed referring to the accompanying drawings, in order to make itmore apparent.

FIGS. 1 to 5 show a comb-shaped product 10 that is a pumping containerincluding a laminated bottle (sometimes called ‘multi-layer bottle’ or‘delamination bottle’) 1 with a delaminating inner layer. The combshaped product 10, viz., the pumping container, is suited for uniformapplication of its content such as a hair-dye to human hair. When a usergrips and presses a body part 1 a of the bottle 1, it will deflate anddeform so as to exude its liquid content through a passage extendingthrough a comb shaped cap 5. This content will thus flow out of aplurality of holes formed in an end portion of the comb. If the userstops gripping and pressing the bottle 1, it recovers its normalconfiguration. Such a character of the bottle 1 is. called“squeezability”. The comb shaped product 10 comprises the comb-shapedcap 5 fitted on a mouth 1 b of the bottle 1. This comb shaped cap 5 iscomposed of a cap portion 5 a fitting on the mouth 1 b, a stem 5 bprotruding from the top of cap portion 5 a and a teeth portion 5 ccontinuing from the stem 5 b. This stem 5 b is made hollow tocommunicate with the interior of the bottle through a discharging mouth6 formed in the cap portion 5 a. The discharging hole 6 has a checkvalve 7, which on one occasion during use allows the liquid content toflow out of the bottle into the comb shaped cap 5, but on the otheroccasion prevents the content from flowing back into the bottle.

As shown in FIGS. 3 and 4, the bottle 1 has a male-threaded portion 8formed integral with its outer periphery around the mouth 1 b. Thisthreaded portion 8 is to be fastened into a mating female-threadedportion 9 that is formed in the inner periphery of the comb shaped cap 5a, to thereby fix the latter on the bottle 1. Round ventilation holes 4are formed in the mouth, below the threaded portion 8 and diametricallyat opposite positions. Those ventilation holes will allow ambient air toflow into a space between an inner layer and an outer layer of thelaminated bottle 1.

As seen in FIGS. 1 and 4, the laminated bottle 1 is composed of theouter layer 2 and the inner layer 3 formed therein. Those inner andouter layers 2 and 3 comprise cylindrical body parts 2 a and 3 a andcylindrical mouth parts 2 b and 3 b, respectively. In other words, thebottle's body 1 a consists of these body parts 2 a and 3 a, with themouth 1 b of bottle similarly consisting of these mouth parts 2 b and 3b. The outer layer 2 may be made of a PET (viz., polyethyleneterephthalate), an EVOH (viz., a copolymer of ethylene and vinylalcohol) or the like. The inner layer 3 is a film prone to exfoliatefrom the outer layer 2 and capable of deformation relative thereto. Amaterial for forming the inner layer 3 may be a polyolefin resin (suchas a polyethylene) of an excellent gas-barrier property. The ventilationholes 4, that are not formed in the inner layer 3, does howeverpenetrate the outer layer 2 from its outer surface to inner surface.Those holes are designed and arranged not to be closed with the combshaped cap 5. The valve body 7 formed integral with the cap 5 faces themouth 1 b of the laminated bottle 1. This valve body 7 will readily openwhen the content within the inner layer 3 flows outwards into the cap 5,but will prevent any amount of the content from returning therefrom tothe interior of inner layer 3.

The ventilation holes 4 in the mouth part 2 b of the outer layer 2 willbe closed temporarily with the inner layer's mouth part 3 b itself frominside. In this mode, the inner layer's mouth part 3 b works as aclosing portion for the ventilation holes 4. However, the mouth part 3 bwill open those holes 4 in response to a negative pressure occasionallyappearing in the space between the outer and inner layer body parts 2 aand 3 a. As a result, atmospheric pressure will deform the said mouthpart 3 b inwardly to depart from the holes, as indicated by the chaindouble-dashed lines in FIG. 5.

The inner layer mouth part 3 b (i.e., the closing portion) in thisembodiment has such a wall thickness and an inner diameter that themouth can elastically recover its home position to close the ventilationholes 4. For instance, the wall thickness of the inner layer mouth part3 b may for instance be about 0.5 mm, with the mouth diameter (i.e., itsinner diameter) being 25 mm. On the other hand, the inner body part 3 amay be made so thin to have a wall thickness of about 0.2 mm in order toreadily deflate and deform itself as the liquid content is discharged.In order for the outer layer body part 2 a to be smoothly depressed, itis made relatively thick to be of a wall thickness of about 0.6 mm andhas an outer diameter of about 45 mm. As for the outer layer mouth part2 b, it is formed to have a thickness of about 3-4 mm so as to be rigidenough to hold the cap 5 thereon.

A flange 31 formed in a central bottom portion of the inner layer 3firmly engages with a corresponding central bottom portion of the outerlayer 2. This flange 31 made of the same resin as the inner layer 3 istherefore an integral portion thereof.

In use of the pumping container 10 described above, a user will grip anddepress the body part 1 a of the laminated bottle 1, in a manner shownin FIG. 6. Consequently, the outer and inner body parts 2 a and 3 a willdeform themselves inwardly in a radial direction. Thus, the liquidcontent held in the inner layer 3 will open the check valve 7 to flowout through the discharging mouth 6 into the comb-shaped cap 5. If theuser stops gripping and depressing the laminated bottle 1 as seen inFIG. 7, the outer layer 2 will recover its normal configuration. Theinner layer 3 will however remain depressed, because the check valve 7is kept closed to prevent the liquid content from returning to theinterior of inner layer 3, also inhibiting ambient air from entering it.As the outer layer 2 tends to restore its natural configuration, anegative pressure will appear in the space between the outer and innerlayer body parts 2 a and 3 a. As a result, atmospheric pressure willforce the inner layer mouth part 3 b inwards to depart from theventilation holes 4 of outer layer 2, consequently allowing ambient airto dash in between the inner and outer layers 3 and 2 through saidholes. Upon full return of the outer layer body part 2 a and sufficientintroduction of ambient air through those holes 4, such a temporarydeformation of the inner layer mouth part 3 b will disappear to allow itto take again its normal and cylindrical shape to shut the holes 4.

If and when the user grips and depresses again the laminated bottle 1later or subsequently, the inner layer mouth part 3 b having closed theventilation holes 4 will inhibit the air present between the outer andinner layer body parts 2 a and 3 a from leaking out of the bottle. Suchan ‘interlayer’ air will thus be compressed by a temporarily decreasedcapacity of the outer layer body 2 a being deformed, so as to depressthe inner layer body part 3 a from outside to force the liquid contentof the inner layer 3 outwardly towards the comb-shaped cap 5.

Even if the liquid content is further discharged out of the container,its inner and outer layers 3 and 2 will remain firmly fixed to eachother at their bottoms as shown in FIG. 8. Owing to this feature, thebottom end portion of the inner layer 3 is prevented from curlingupwards, while allowing the liquid content to be completely exhaustedand enabling visual inspection of the interior of container to know fromtime to time how much content is left therein.

The laminated bottle 1 discussed above may preferably be produced by theinjection-stretch-blow molding method. Desirably, a parison ‘P’ of sucha structure as shown in FIG. 9 may be blow molded to give that bottle.This parison ‘P’ is prepared by injection molding at first a cylindricalouter layer preform ‘2P’ and subsequently a cylindrical inner layerpreform ‘3P’ therein, each preform having its closed bottom. Theventilation holes 4 are preferably formed when injection molding theouter layer preform 2P. It is also preferable herein to form the flange31 when molding the inner layer preform 3P, by using a mold whose femalesegment (viz., a cavity segment) has a recess around its gate forinjecting a resin to form said inner layer preform. The inner layerpreform 3P may be prepared by injecting a molten resin inside the outerlayer preform 2P through a through-hole ‘P1’ that has previously beenformed to penetrate a central portion of the outer preform's bottom.

Next, FIGS. 10 to 16 will be referred to in describing a mold designedto preliminarily form a parison, as well as a method of and an apparatusfor making the laminated bottles using the parison. A rotary plate 50 issupported on a frame not shown and intermittently driven in onedirection. This plate 50 from which a lip segment 51 (namely, a threadedsegment) depends will cause it to circulatingly move between aninjection station, a blowing station, and a discharging station,sequentially in this order. The lip segment 51 consists of a pair ofsplit halves that are engageable with and disengageable from each otherin a transverse direction, so as to be closed or opened by means of adriving mechanism not shown. In its closed position, that segment willhold therein from time to time either the mouth part of the un-stretchedparison or that of the stretched parison, viz., a laminated bottle. Sucha lip segment 51 is operatively connected to the bottom surface of therotary plate 50.

At the injection station, the outer and inner layer preforms 2P and 3Pare molded. In this embodiment, the injection station is divided into afirst substation (viz., an apparatus or device for injection molding theouter layer 2P) and a second substation (viz., a further apparatus formolding the inner layer preform 3P). In detail, the injection moldedouter layer preform 2P will be taken out at first after opening itsmold. Then, this preform will be transported to and placed in anothermold so that the inner layer preform 3P is injection molded therein toprovide a laminated parison consisting of these preforms 2P and 3P to beblow molded subsequently.

FIGS. 10 and 11 show the process of injection molding the outer layerpreform 2P at the first substation. In the drawings, an injection coresegment 60 (viz., a male mold), the lip segment 51, and a cavity segment61 (viz., a female mold) are disposed up and down in this order. Afterfastening these segments to each other in this way, an amount of moltenresin will be propelled from an extruder nozzle 62 into the cavity,through a hot runner 63, a nozzle 64 thereof and the gate 65, to therebyproduce the outer layer preform 2P.

The cavity segment 61 has two horizontal apertures 66 formed therein toreceive pins 67 as the projected members capable of sliding in theiraxial direction. An inner end portion of each pin 67 protrudes throughthe cavity segment to contact the core segment 60 when (before or after)feeding a molten resin. This means that these pins 67 do act to piercethrough-holes (i.e., the ventilation holes) 4 already at the step ofmolding the outer layer preform 2P. In the illustrated embodiment,solenoids 68 drives the respective pins 67 towards and away from theirprojected position. Each of those solenoids 68 will be actuated with anelectric current so as to cause the corresponding pin 67 to projecttowards the cavity until it contacts the core segment 60. By ceasingapplication of electric current to the solenoids, the pins 67 will beretracted and embedded in the cavity segment. Alternatively, a springfor urging each pin towards its retracted position can be employed, as amatter of course, in combination with a means for supplying a compressedair for driving the pin 13 inwardly. It may also be possible to employpins each having an arcuate inner end corresponding to curvature of theinjection core.

A further pin 69 is provided in connection with the core segment 60 soas to extend longitudinally through a central region thereof. Thisfurther pin 69 is slidably held in the core segment 60 so as to berepositioned intermediately between its retracted position whollyembedded in the core segment 60 and its projected position protruding inpart therefrom to be pressed on the gate 65. After the cavity is filledwith an amount of molten resin, the further pin 69 facing the gate 65will be forced into the cavity segment so as to seal the gate 65. Thepreform's central bottom portion that is temporarily occupied by the pin69 can never be filled with the resin for forming the outer layerpreform 2P. This portion will define the through-hole P1 to be producedin the bottom center of the preform 2P. Thus, the through-hole P1 isformed by the further pin 69 already at the step of molding the outerlayer preform 2P. Also, this further pin 69 may be driven between itsprojected and retracted positions by a solenoid, or alternatively by aspring cooperating with a compressed air, or by any other appropriatemechanism.

FIG. 12 illustrates how to injection mold the inner layer preform 3P atthe second substation. Also in this figure of the drawings, theinjection core 70, the lip segment 51 and the cavity segment 71 arearranged up and down in this order. The cavity segment has closing pins72 formed therein and facing the respective ventilation holes 4 thathave been formed in the outer layer preform 2P, wherein those closingpins 72 can be projected and retracted. When projected, the inner endsof the closing pins stand in flush with the inner surface of outer layerpreform 2P that has been inserted into the cavity segment 71. Whenretracted, those pins 72 are embedded in this cavity segment.

The inner layer preform will be molded in such a manner that the outerlayer preform 2P is preliminarily placed in the unfastened cavitysegment 71 and then the ventilation holes 4 are accurately located toface the closing pins 72. Subsequently, these pins will advance to taketheir projected position so as to clog the ventilation holes 4. Afterhaving fastened the core and cavity segments 70 and 71 together in avertical direction, an amount of another molten resin will be injectedthrough an extruder nozzle 73. This resin advances through a hot runner74, a runner nozzle 75 and a gate 76 so as to enter the cavity. In thisway, the molten resin dashing in the interior of outer layer preform 2Pthrough the hole P1 formed therein will form the inner layer preform 3P.The core segment 70 for molding the inner layer is slightly smaller inouter diameter than that 60 for molding the outer layer. The differencein diameter determines the wall thickness of the inner layer preform 3P.The cavity segment 71 has a recess 77 facing the through-hole P1 thathas been formed in the preform 2P, so that the gate 76 is located in thebottom of recess 77. This gate is positioned below and spaced from thethrough-hole P1 to be spaced therefrom. Therefore, the flange 31 made ofthe resin forming the inner layer preform 3P will be disposed outsidethe through-hole P1 in the outer layer preform 2P. In the example shownin the drawings, the flange 31 protrudes outwards from the through-holeP1, though another fashion of injection molding may alternatively beemployed so that the flange has its outer end surface in flush with theouter surface of outer layer preform 2P. The mold for forming the innerlayer preform 3P may not necessarily be specially designed as to itsgate 76, but any ordinary pin gate (viz., direct gate) may be employed.

The mold having operated to form the inner layer preform 3P will then beopened to have the pins 72 retracted out of the cavity, but allowing thelip segment 51 to continue to hold a parison ‘P’ consisting of the outerand inner layer preforms 2P and 3P thus laminated on each other.

At the blowing station shown in FIGS. 13 to 15, there are provided ablow core segment 81 having a stretching rod 80 attached thereto, thelip segment 51 holding the parison ‘P’, a blow cavity segment 82, and abottom segment 83. These segments are, also at this station, arranged upand down. After having fixed these segments together and placed theparison ‘P’ in the blow cavity segment 82, this parison will be heatedto a given temperature. Thereafter, the stretching rod 80 is drivendownwards to have its end 81 positioned in the parison ‘P’. This rodwill push down the parison bottom to effect the so-called ‘longitudinalstretching’ process. Subsequent to this process, a compressed air willbe introduced through the blow core 81 into the parison, to therebyexpand same to undergo the ‘transversely stretching’ process. Howeverduring these processes, the parison's minor portion where theventilation holes 4 have been formed (near the lower end of thecontainer's mouth part) are firmly held in position by the lip segmentwithin the blow cavity segment 82. Thus, the stretching for orientationis only effected in the parison's major region located below said minorportion, but not effected therein around the ventilation holes 4. Afterhaving been stretched, the parison will be cooled down to give afinished laminated bottle 1.

At the discharging station for taking out molded products as shown inFIG. 16, an ejector rod 90, the lip segment 51 for holding the laminatedbottle 1, and a transporting apparatus 91 like a conveyor belt arearranged also vertically in this order. The ejector rod 90 has anejecting foot 92 at its inner end. This foot 92 will fit in the mouthpart 1 b of bottle, before opening the lip segment 51 in a horizontaldirection to put the bottle 1 down on the conveyor 91.

As discussed above in detail, the ventilation holes 4 will have alreadybeen formed at the step of molding the outer layer preform 2P so thatthe inner layer will never be injured as in the prior art when formingsaid holes. Further, works for manually piercing such holes one by onein the injection molded outer layer 2P after completing the laminatedbottle 1 are no longer necessary, thus enhancing manufacture efficiency.After molding the delaminating inner layer preform 3P on the innersurface of outer layer preform, the stretching for orientation of thepreforms is carried out only for a region thereof located below theventilation holes 4. By virtue of this feature, the inner layer's regionwhere the ventilation holes in the outer layer are present will keep itsoriginal or ‘non-stretched’ thickness. Such a relatively thicker regionwill satisfactorily function as ‘valve bodies’ cooperating withventilation holes 4, so that manufacture process is now rendered moresimple and less expensive than in the case of preparing and attachingdiscrete valves. In addition, the inner end of the pin 72 is positionedherein to be generally in flush with the inner surface of outer layerpreform 2P during the molding of inner layer preform 3P. Accordingly,the resin forming this preform will be prevented from filling vacantspaces that have been previously formed in the outer layer preform 2P soas to serve later as the ventilation holes 4 in a finished product.

The pins disposed in the cavity segment in the embodiment describedabove may be replaced with another pair of pins that are disposed in thelip segment to contact the sides of injection core. Alternatively, theinjection core may be equipped with substituting pins in such a way asto contact the inner surface of the lip segment. Since the lip segmentconsists of split into halves separable in a transverse direction,appropriate rod or like protrusion may be fixed in place in parallelwith this direction, allowing it to contact the core segment as the lipsegment is driven to take its fastened position. The present inventionexemplified in the embodiments is applied to the laminated containerthat comprised the single outer layer and the single inner layer.However, the invention can also apply to any other type container whoseouter and/or inner layers are composed each of two or more layers orstrata.

In the described embodiments, the ventilation holes 4 are formed in themouth part of the container. However, they may alternatively be formedin any portion of the container if its inner layer is designed tofunction as a valve body. For example, the ventilation holes 4 may beformed in the bottom of the bottle.

What is claimed is:
 1. A laminated bottle comprising: an outer layer andan inner layer laminated on an inner surface of the outer layer, whereinthe inner layer is capable of delaminating from the outer layer, aventilation hole is formed in the outer layer to allow ambient air toflow into a space between the outer layer and the inner layer, theventilation hole is normally closed from inside with a portion of theinner layer blocking said ventilation hole, the closing portion of theinner layer functions as a valve that is capable of inward deforming dueto atmospheric pressure in response to a negative pressure appearing inthe space and returning to blocking said ventilation hole after saidnegative pressure appears in the space, and the ventilation hole opensas a result of the deforming of the valve.
 2. A laminated bottle asdefined in claim 1, wherein the closing portion of the inner layer haselasticity for recovery so as to close the ventilation hole.
 3. Alaminated bottle as defined in claim 1, wherein each of the outer layerand the inner layer substantially comprises of a body part and a mouthpart.
 4. A laminated bottle, comprising: an outer layer and an innerlayer laminated on an inner surface of the outer layer, wherein each ofthe outer layer and the inner layer substantially comprises of a bodypart and a mouth part; wherein the inner layer is capable ofdelaminating from the outer layer, a ventilation hole is formed in themouth part of the outer layer to allow ambient air to flow into a spacebetween the outer layer and the inner layer, the ventilation hole isnormally closed from inside with a portion of the inner layer, theclosing portion of the inner layer functions as a valve that is capableof inward deforming due to atmospheric pressure in response to anegative pressure appearing in the space, the ventilation hole opens asa result of the deforming of the valve, the mouth part of the innerlayer acts as the portion for closing the ventilation hole, and themouth part of the inner layer is thicker than the body part of the innerlayer.
 5. A laminated bottle as defined in claim 4, wherein the bodypart of the inner layer is thinner than the mouth part of the innerlayer to be of a film-like shape, and a portion of the mouth part of theinner layer, which is located adjacent to the ventilation hole, isthicker than the body part of the inner layer so as to be capable ofelastic recovery.
 6. A laminated bottle, comprising: an outer layer andan inner layer laminated on an inner surface of the outer layer, whereineach of the outer layer and the inner layer substantially comprises of abody part and a mouth part and each of the mouth parts of the outerlayer and the inner layer is of a cylindrical shape; wherein the innerlayer is capable of delaminating from the outer layer, a ventilationhole is formed in the mouth part of the outer layer to allow ambient airto flow into a space between the outer layer and the inner layer, theventilation hole is normally closed from inside with a portion of theinner layer, the closing portion of the inner layer functions as a valvethat is capable of inward deforming due to atmospheric pressure inresponse to a negative pressure appearing in the space, the ventilationhole opens as a result of the deforming of the valve, and the mouth partof the inner layer acts as the portion for closing the ventilation hole.7. A laminated bottle as defined in claim 6, wherein the body part ofthe inner layer is thinner than the mouth part of the inner layer to beof a film-like shape, and a portion of the mouth part of the innerlayer, which is located adjacent to the ventilation hole, is thickerthan the body part of the inner layer so as to be capable of elasticrecovery.
 8. A laminated bottle as defined in claim 1, wherein thebottle is formed by the injection-stretch-blow-molding method, each ofthe inner layer and the outer layer has a bottom, the bottom of theinner layer has a flange fixed on the bottom of the outer layer, theflange is formed when molding a inner preform for forming the innerlayer by injecting a molten resin to an interior of an outer preform forforming the outer layer through a through-hole that is previously formedin a bottom of the outer preform.
 9. A pumping container comprising: alaminated bottle comprising of an outer layer and an inner layerlaminated on an inner surface of the outer layer; and a cap fitted onthe mouth part of the laminated bottle, wherein the inner layer iscapable of delaminating from the outer layer; a ventilation hole isformed in the outer layer to allow ambient air to flow into a spacebetween the outer layer and the inner layer; the ventilation hole isnormally closed from inside with a closing portion of the inner layer;the closing portion of the inner layer blocking said ventilation hole tofunction as a valve that is capable of inward deforming due toatmospheric pressure in response to a negative pressure appearing in thespace and returning to blocking said ventilation hole after saidnegative pressure appears in the space, the ventilation hole opens as aresult of the deforming of the valve; each of the outer layer and theinner layer is substantially comprising of a body part and a mouth part;the body part of the outer layer is capable of being deformed so as todeflate; the cap has an outlet orifice for discharging a content storedwithin the inner layer of the laminated bottle, and a check valve isattached to the outlet orifice.
 10. A pumping container as defined inclaim 9, wherein the closing portion of the inner layer has elasticityfor recovery so as to close the ventilation hole.
 11. A pumpingcontainer comprising: a laminated bottle comprising of an outer layerand an inner layer laminated on an inner surface of the outer layer,each of the outer layer and the inner layer being substantiallycomprised of a body part and a mouth part; and a cap fitted on the mouthpart of the laminated bottle, wherein the inner layer is capable ofdelaminating from the outer layer; a ventilation hole of the laminatedbottle formed in the mouth part of the outer layer to allow ambient airto flow into a space between the outer layer and the inner layer; theventilation hole is normally closed from inside with a closing portionof the inner layer, the mouth part of the inner layer acts as theportion for closing the ventilation hole, and the mouth part of theinner layer is thicker than the body part of the inner layer; theclosing portion of the inner layer functions as a valve that is capableof inward deforming due to atmospheric pressure in response to anegative pressure appearing in the space, the ventilation hole opens asa result of the deforming of the valve; the body part of the outer layeris capable of being deformed so as to deflate; the cap has an outletorifice for discharging a content stored within the inner layer of thelaminated bottle, and a check valve is attached to the outlet orifice.12. A pumping container as defined in claim 11, wherein the body part ofthe inner layer is thinner than the mouth part of the inner layer to beof a film-like shape, and a portion of the mouth part of the innerlayer, which is located adjacent to the ventilation hole, is thickerthan the body part of the inner layer so as to be capable of elasticrecovery.
 13. A pumping container comprising: a laminated bottlecomprising of an outer layer and an inner layer laminated on an innersurface of the outer layer; and a cap fitted on the mouth part of thelaminated bottle, wherein the inner layer is capable of delaminatingfrom the outer layer; a ventilation hole is formed in the outer layer toallow ambient air to flow into a space between the outer layer and theinner layer; the ventilation hole is normally closed from inside with aclosing portion of the inner layer; the closing portion of the innerlayer functions as a valve that is capable of inward deforming due toatmospheric pressure in response to a negative pressure appearing in thespace, the ventilation hole opens as a result of the deforming of thevalve; each of the outer layer and the inner layer is substantiallycomprising of a body part and a mouth part; the body part of the outerlayer is capable of being deformed so as to deflate; the cap has anoutlet orifice for discharging a content stored within the inner layerof the laminated bottle, and a check valve is attached to the outletorifice; each of the mouth parts of the outer and inner layers is of acylindrical shape, the ventilation hole is formed in the mouth part ofthe outer layer, and the mouth part of the inner layer acts as theportion for closing the ventilation hole.
 14. A pumping container asdefined in claim 13, wherein the body part of the inner layer is thinnerthan the mouth part of the inner layer to be of a film-like shape, and aportion of the mouth part of the inner layer, which is located adjacentto the ventilation hole, is thicker than the body part of the innerlayer so as to be capable of elastic recovery.
 15. A pumping containeras defined in claim 9, wherein the closing portion of the inner layer iscapable of being pressed outwards by the content being discharged so asto close the ventilation hole of the outer layer by the pressed portion.16. A pumping container as defined in claim 9, wherein each of the innerlayer and the outer layer of the laminated bottle has a bottom, and thebottoms of the inner layer and the outer layer are fixed to each otherso as to prevent a lower end portion of the inner layer from curling up.